This study aimed at uncovering complexities surrounding in-service English as a foreign language (EFL) teachers' identity development. Literature still lacks knowledge about such process in the face of workplace conflicts and as to whether such conflicts vacillate EFL teachers' imagined and practiced identities, especially in the context of Iran. To address this lacuna, three Iranian EFL teachers' identity construction in the course of 4 years was explored through narrative inquiry. Data were collected through journals, narrative semi-structured interviews, and lesson plans. Drawing upon Activity Theory (AT), the findings underscored the fluid, collaborative, and negotiated nature of identity development. This study demonstrated how workplace climate, teaching milieus and power relations within, teachers' personal ideologies and interpretations, and institutional demands may be used to garner insight into EFL teachers' journey of professional identity development. This study has implications for educational authorities and teacher educators.